| A | B |
|---|
| the product of distance and the force in the direction an object moves | work |
| the SI unit for force, equal to 1 newton-meter | joule |
| the rate of doing work | power |
| the SI unit of power, equal to one joule per second | watt |
| a common unit of power, equal to about 746 watts | horsepower |
| a device that changes a force | machine |
| the force exerted on a machine | input force |
| the distance through which the input force acts in a machine | input distance |
| the work done on a machine as the input force acts through the input distance | work input |
| the force exerted by a machine | output force |
| the distance an output force acts through in a machine | output distance |
| the work done by a machine as the output force acts through the output distance | work output |
| the number of times that a machine increases an input force | mechanical advantage |
| the ratio of the output force to the input force in a machine | actual mechanical advantage |
| the mechanical advantage of a machine in the absence of friction | ideal mechanical advantage |
| the percentage of the work input that becomes work output in a machine | efficiency |
| a rigid bar that is free to move around a fixed point | lever |
| the fixed point a lever rotates around | fulcrum |
| the distance between the fulcrum in a lever and the input force | input arm |
| the distance between the fulcrum in a lever and the output force | output arm |
| a simple machine that consists of two rigidly attached disks or cylinders, each one with a different radius | wheel and axle |
| a slanted surface along which a force moves an object to a different elevation | inclined plane |
| a V-shaped object whose sides are two inclined planes sloped toward each other | wedge |
| an inclined plane wrapped around a cylinder | screw |
| a simple machine that consists of a rope that fits into a groove in a wheel | pulley |
| a combination of two or more simple machines that operate together | compound machine |
